Mahjong was added as a bonus mini-game because they had the code for it.
Just because YOU don't like it does not mean that the mini-game will die.
"The game is too complex and No tutorial."
And I highly doubt that you even tried to play to barely see that it does have a complete tutorial and additionally has a suggestion to the next step, for every step. I literally won a game vs other players just following the hints, and doing some decisions based on how they teach me to think how to play.
"Innate unfairness"
There's literally a rank system and a difficulty level vs NPC for you to choose. What does you need more?
"Time"
Mahjong is about fun and chill, there's no rewards other than achievements. If it's not your cup or tea move along.
"Bad automated suggestions"
You can disable it if you think it's bad. I think that the suggestions are amazing for me to learn. You can either blindly follow them and learn nothing and post a new thread about Mahjong on the forum, or you can play and try to think a barely minimum to see what's the meaning of the suggestion and start to move the pieces by yourself.
"convoluted rules and Why can't we just have a minigame that anyone can pick up in seconds"
For every mini-game there's a COMPLETE progression system. You can either stay forever at the beginner level and STILL be rewarded just fine, or you can start to try to understand how it works if you like it and reach high levels.
At the end of your thread I can't think of anything else than that you just want to get things handed to you with minimum mental effort, because these mini-game are not THAT hard to get the basics and get rewarded just fine. You don't need to be the best one, if you have fun, then it's all that matters. If you're not having fun, and other are, move along.
And @Reynhart, you can enter Gold Saucer with the free trial account to play ANY mini-game. It's literally a completely free content. There's nothing anyone should or can complain about it. Just don't play if you don't like, Play if you like.